1. Field of the Invention
The present invention relates to a communication system where a communication terminal sends a connection request for establishment of a connection, and more particularly to a method of selecting a communication terminal among plural communication terminals when there are plural connectable communication terminals.
2. Description of the Related Art
In recent years, real-time communication, where a user can make a call whenever he/she wants to communicate on real-time, becomes increasingly diversified. The diversification of real-time communication technologies is realizing various applications. For example, the users of TV telephones can send not only the sounds which can be sent via a conventional telephone but also video via the TV telephones. The real-time communication, in addition to such applications, is realizing free exchanges of audio, video, and other data on an Internet Protocol (IP) network.
Together with the deepening diversification of technology, various communication terminals are developed. Today, employable communication terminals are not only dedicated terminals such as conventional telephones used exclusively for the voice call, but also general-purpose devices such as personal computers. Further with the diversification in transmitted information, it appears to be more convenient if each of various types of information is handled with a separate communication terminal among plural communication terminals. With such process sharing, dedicated terminal (e.g., a dedicated TV telephone) provided exclusively for each type of communication such as a TV call, becomes unnecessary. Then, the user may be able to prepare plural communication terminals with suitable functions, and on receiving a call, make a selection from the plural communication terminals as appropriate according to an environment (for example, the user may choose a conventional telephone and a portable personal digital assistant (PDA)).
When processing of various pieces of information is required and the users have choices of plural communication terminals as candidate tools to be employed at answering a call, the user may find it more convenient if he/she can choose one or more of the provided communication terminals for each call. In addition, since the user does not always stay at a predetermined location nor carry a predetermined set of communication terminals at a time of call, a system should be provided where the user can select the communication terminal(s) to use for each call.
However, if there are too many selectable candidate communication terminals, such selection creates a considerable workload and significantly delays the eventual establishment of connection for the call. In addition, when there are too many selectable candidate communication terminals, the user may find it difficult to select he/she really wants to use.
For example, Japanese Patent Application Laid-Open No. 08-331124 discloses an apparatus to automatically secure a necessary communication bandwidth corresponding to a communication terminal which is used by a participant of a television conference.
When the connection needs to be established with the caller communication terminal, the user him/herself needs to perform a predetermined operation to select a communication terminal to be connected from plural candidate communication terminals. Hence significant time and workload are required until an eventual establishment of the call.